<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
 
<style>
    * {
      margin: 0;
      padding: 0;

    }

    #div1left {
      background-color: burlywood;
      height: 300px;
      width: 300px;
      float: left;
    }

    #div2right {
      background-color: aquamarine;
      height: 300px;
      width: 300px;
      float: right;
    }
    #div3center{
      background-color: blueviolet;
      height: 300px;
      margin-left: 310px;
      margin-right: 310px;


    }
  </style>
</head>

<body>

  <div>
    <div id="div1left">1</div>
    <div id="div2right">2</div>
    <div id="div3center"></div>
  </div>
</body>
</html>